On the twenty-third day of the month of September, in an early year of a decade not too long before our own, the human race suddenly encountered a deadly threat to its very existence. And this terrifying enemy surfaced, as such enemies often do, in the seemingly most innocent and unlikely of places.

So begins the opening narration to Little Shop of Horrors. On the twenty-third day of the month of September, in this year, we thought we’d take a look at the backstory of this amazing classic.

How in the world did they manage to make a movie out of Little Shop of Horrors? The premise of the film is so absurd — an evil plant arrives on Earth to demand human blood from an unassuming botanist and take over the planet — that it seems like the whole thing is one big joke.

And in fact, it is a joke. Sort of. The movie’s origins date back to 1960, when super-low-budget director Roger Corman was given access to some sets that were used to shoot another film. Working fast, Corman came up with a horror-comedy idea based on his time hanging out in LA coffee shops. Originally, it was about a vampire music critic; then it was about a chef who cooked his customers; and then finally the chef was made into a plant so that the violence wouldn’t run afoul of censors.

They were reportedly drunk by the time they finished outlining the story.

Most of the actors in the Corman version were stock actors from previous Corman projects, and he had to schedule the shoot quickly in order to avoid changing industry laws that would require him to pay the actors more for their appearances. Jack Nicholson makes a brief appearance, and says that he “just did a lot of weird shit.”

Twenty years went by after the film was released, and then suddenly it was back — but on stage. Alan Menken and Howard Ashman created a satire of the old schlocky ’60s horror films, set it to music, and it was an unbelievable hit. It was only a matter of time before a remake was due, given that the stage version was produced by movie mogul David Geffen.

Initially, Martin Scorsese was supposed to direct the movie in 3-D; after that, John Landis was tapped. But the role eventually fell to Frank Oz of the Muppets, who transformed it from a stage musical to a big-screen extravaganza. Other first-choices who passed on the project: Cyndi Lauper and Barbra Streisand, who both turned down the part of Audrey.

They shot on the enormous 007 Stage at Pinewood Studios, and discovered that the soundstage was so large it couldn’t be heated properly. The actors’ breath would fog as it came out of their mouths, so they had to suck on ice cubes before a take so that there wouldn’t be a temperature difference.

But the most impressive undertaking was the huge plant puppet. Audrey II is shot at half-speed, and then the footage is sped up so that the puppet can appear to move more rapidly. There are 60 technicians operating it.

The film’s biggest controversy surrounds the ending, which was originally a real bummer. The leads are killed and the Earth is destroyed — and audiences hated it. A happy ending was hastily re-shot, but the “real” original ending still lingered out there in the world. In 1998, a DVD release included some black and white footage from a terrible low-quality dub. When he found out about it David Geffen demanded that it be recalled.

Finally in 2012, Warner Brothers released a mostly-restored version of the ending, albeit with some tweaks, in glorious full HD. It’s a bizarre cap on the life of a story that was only supposed to be some cheap filler written around some used-up sets.